light MERCEDES-BENZ CLA 2019 Owners Manual

Only replace a battery with a battery that hasbeen recommended by Mercedes-Benz.
Remove the SmartKey if you park the vehicleand do not require any electrical consumers.The vehicle will then use very little energy, thusconserving battery power.
If the power supply has been interrupted, e.g. ifyou reconnect the battery, you will have to:
Rset the clock using the multimedia system(see the Digital Operator's Manual)
Rreset the function for folding the exterior mir-rors in/out automatically, by folding the mir-rors out once (Ypage 98)
Charging the battery
GWARNING
During charging and jump-starting, explosive
gases can escape from the battery. There is a
risk of an explosion.
Particularly avoid fire, open flames, creating
sparks and smoking. Ensure there is sufficient
ventilation while charging and jump-starting.
Do not lean over a battery.
GWARNING
Battery acid is caustic. There is a risk of injury.
Avoid contact with skin, eyes or clothing. Do
not inhale any battery gases. Do not lean over
the battery. Keep children away from batter-
ies. Wash away battery acid immediately with
plenty of clean water and seek medical atten-
tion.
GWARNING
A discharged battery can freeze at tempera-
tures below freezing point. When jump-start-
ing the vehicle or charging the battery, gases
can escape from the battery. There is a risk of
an explosion.
Allow the frozen battery to thaw out before
charging it or jump-starting.
!Only use battery chargers with a maximumcharging voltage of 14.8 V.
!Only charge the battery using the jump-starting connection point.
The jump-starting connection point is in theengine compartment (Ypage 282).
XOpen the hood.
XConnect the battery charger to the positiveterminal and ground point in the same orderas when connecting the donor battery in thejump-starting procedure (Ypage 282).
If the indicator/warning lamps do not light up inthe instrument cluster at low temperatures, it isvery likely that the discharged battery has fro-zen. In this case you may neither jump-start thevehicle nor charge the battery. The service life ofa thawed-out battery may be shorter. The start-ing characteristics can be impaired, particularlyat low temperatures. Have the thawed-out bat-tery checked at a qualified specialist workshop.
Only charge the installed battery with a batterycharger which has been tested and approved byMercedes-Benz. A battery charger unit speciallyadapted for Mercedes-Benz vehicles and testedand approved by Mercedes-Benz is available asan accessory. It permits the charging of the bat-tery in its installed position. Contact an author-ized Mercedes-Benz Center for further informa-tion and availability. Read the battery charger'soperating instructions before charging the bat-tery.
Replacing the 12 V battery
Observe the notes on the 12 V battery(Ypage 279).
Mercedes-Benz recommends that you have the12 V battery replaced at a qualified specialistworkshop, e.g. at an authorized Mercedes-BenzCenter.
If you want to replace the battery yourself,observe the following notes:
RAlways replace a defective battery with a bat-tery which meets the specific requirements ofthe vehicle.
The vehicle is equipped with a battery usingAGM (absorbent glass mat) technology or abattery using EFB (enhanced flooded battery)technology. Full vehicle functionality is guar-anteed only with an AGM or EFB battery. Ifreplacement is necessary, always use the bat-tery technology originally installed. Switchingbetween the battery technologies is not per-mitted. For safety reasons, Mercedes-Benzrecommends that you only use batteries
Battery (vehicle)281
Breakdown assistance
Z

If the indicator/warning lamps do not light up in the instrument cluster at low temperatures, it is verylikely that the discharged battery has frozen. In this case you may neither jump-start the vehicle norcharge the battery. Let the battery thaw first. The service life of a thawed-out battery may be shorter.The starting characteristics can be impaired, particularly at low temperatures. Have the thawed-outbattery checked at a qualified specialist workshop.
Do not start the vehicle using a rapid charging device. If your vehicle's battery is discharged, theengine can be jump-started from another vehicle or from a second battery using jumper cables.Observe the following points:
RThe battery is not accessible in all vehicles. If the other vehicle's battery is not accessible, jump-start the vehicle using a second battery or a jump-starting device.
RYou may only jump-start the vehicle when the engine and exhaust system are cold.
RDo not start the engine if the battery is frozen. Let the battery thaw first.
ROnly jump-start from batteries with a 12 V voltage rating.
ROnly use jumper cables that are not damaged and have a sufficient cross-section and insulatedterminal clamps.
RMake sure that the two vehicles do not touch.
Make sure that:
RThe jumper cables are not damaged.
RNon-insulated parts of the terminal clamps do not come into contact with other metal parts whilethe jumper cables are connected to the battery.
RThe jumper cables cannot come into contact with parts that can move when the engine is running,such as the V-belt pulley or the fan.
XSecure the vehicle by applying the electric parking brake.
XShift the transmission to position].
XTurn the SmartKey to positionZin the ignition lock and remove it.
XSwitch off all electrical consumers, e.g. rear window defroster, lighting, etc.
XOpen the hood.
Jump-starting283
Breakdown assistance
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If the tire pressures have been set to the lowervalues for lighter loads and/or lower roadspeeds, the pressures should be reset to thehigher values:
Rif you want to drive with an increased loadand/or
Rif you want to drive at higher speeds
iThe tire pressures for increased loads and/or higher road speeds, shown in the tire pres-sure table, may have a negative effect on driv-ing comfort.
If the tire pressure is not set correctly, this canlead to an excessive build-up of heat and a sud-den loss of pressure.
For more information, contact a qualified spe-cialist workshop.
Important notes on tire pressure
GWARNING
If the tire pressure drops repeatedly, the
wheel, valve or tire may be damaged. Tire
pressure that is too low may result in a tire
blow-out. There is a risk of an accident.
RCheck the tire for foreign objects.
RCheck whether the wheel is losing air or the
valve is leaking.
If you are unable to rectify the damage, con-
tact a qualified specialist workshop.
GWARNING
If you fit unsuitable accessories onto tire
valves, the tire valves may be overloaded and
malfunction, which can cause tire pressure
loss. Due to their design, retrofitted tire pres-
sure monitors keep the tire valve open. This
can also result in tire pressure loss. There is a
risk of an accident.
Only screw the standard valve cap or other
valve caps approved by Mercedes-Benz for
your vehicle onto the tire valve.
Use a suitable pressure gauge to check the tirepressure. The outer appearance of a tire doesnot permit any reliable conclusion about the tirepressure. On vehicles equipped with the elec-tronic tire pressure monitor, the tire pressurecan be checked in the on-board computer.
The tire temperature and pressure increasewhen the vehicle is in motion. This is dependenton the driving speed and the load.
Therefore, you should only correct tire pres-sures when the tires are cold.
The tires are cold:
Rif the vehicle has been parked with the tiresout of direct sunlight for at least three hoursand
Rif the vehicle has been driven less than 1 mile(1.6 km)
The tire temperature changes depending on theoutside temperature, the vehicle speed and thetire load. If the tire temperature changes by18 ‡ (10 †), the tire pressure changes byapproximately 10 kPa (0.1 bar/1.5 psi). Takethis into account when checking the pressure ofwarm tires. Only correct the tire pressure if it istoo low for the current operating conditions. Ifyou check the tire pressure when the tires arewarm, the resulting value will be higher than ifthe tires were cold. This is normal. Do notreduce the tire pressure to the value specifiedfor cold tires. The tire pressure would otherwisebe too low.
Observe the recommended tire pressures forcold tires:
Ron the Tire and Loading Information placardon the B-pillar on the driver's side
Rin the tire pressure table in the fuel filler flap(Ypage 141)
Underinflated or overinflated tires
Underinflated tires
GWARNING
Tires with pressure that is too low can over-
heat and burst as a consequence. In addition,
they also suffer from excessive and/or irreg-
ular wear, which can severely impair the brak-
ing properties and the driving characteristics.
There is a risk of an accident.
Avoid tire pressures that are too low in all the
tires, including the spare wheel.
Underinflated tires may:
Roverheat, leading to tire defects
Radversely affect handling
Tire pressure295
Wheels and tires
Z

Information on tire pressures is displayed in themultifunction display. After a few minutes ofdriving, the current tire pressure of each tire isshown in theServ.Serv.menu of the multifunctiondisplay, see illustration (example).
For information on the message display, refer tothe "Checking the tire pressure electronically"section (Ypage 299).
Important safety notes
GWARNING
Each tire, including the spare (if provided),
should be checked at least once every two
weeks when cold and inflated to the pressure
recommended by the vehicle manufacturer
on the Tire and Loading Information placard
on the driver's door B-pillar or the tire pres-
sure label on the inside of the fuel filler flap. If
your vehicle has tires of a different size than
the size indicated on the Tire and Loading
Information placard or, if available, the tire
pressure label, you should determine the
proper tire pressure for those tires.
As an added safety feature, your vehicle has
been equipped with a tire pressure monitoring
system (TPMS) that illuminates a low tire pres-
sure telltale when one or more of your tires
are significantly underinflated. Accordingly,
when the low tire pressure telltale lights up,
you should stop and check your tires as soon
as possible, and inflate them to the proper
pressure. Driving on a significantly underin-
flated tire causes the tire to overheat and can
lead to tire failure.
Underinflation also reduces fuel efficiency
and tire tread life, and may affect the vehicle's
handling and stopping ability. Please note that
the TPMS is not a substitute for proper tire
maintenance, and it is the driver's responsi-
bility to maintain correct tire pressure, even if
underinflation has not reached the level to
trigger illumination of the TPMS low tire pres-
sure telltale.
Your vehicle has also been equipped with a
TPMS malfunction indicator to indicate when
the system is not operating properly. The
TPMS malfunction indicator is combined with
the low tire pressure telltale. When the sys-
tem detects a malfunction, the warning lamp
will flash for approximately a minute and then
remain continuously illuminated. This
sequence will be repeated every time the vehi-
cle is started as long as the malfunction
exists. When the malfunction indicator is illu-
minated, the system may not be able to detect
or signal low tire pressure as intended.
TPMS malfunctions may occur for a variety of
reasons, including the installation of incom-
patible replacement or alternate tires or
wheels on the vehicle that prevent the TPMS
from functioning properly. Always check the
TPMS malfunction telltale after replacing one
or more tires or wheels on your vehicle to
ensure that the replacement or alternate Tires
and wheels allow the TPMS to continue to
function properly.
It is the driver's responsibility to set the tirepressure to that recommended for cold tireswhich is suitable for the operating situation(Ypage 293). Note that the correct tire pressurefor the current operating situation must first betaught-in to the tire pressure monitor. If a sub-stantial loss of pressure occurs, the warningthreshold for the warning message is aligned tothe taught-in reference values. Restart the tirepressure monitor after adjusting the pressure ofthe cold tires (Ypage 300). The current pres-sures are saved as new reference values. As aresult, a warning message will appear if the tirepressure drops significantly.
The tire pressure monitor does not warn you ofan incorrectly set tire pressure. Observe thenotes on the recommended tire pressure(Ypage 293).
The tire pressure monitor is not able to warn youof a sudden loss of pressure, e.g. if the tire ispenetrated by a foreign object. In the event of asudden loss of pressure, bring the vehicle to a
298Tire pressure
Wheels and tires

halt by braking carefully. Avoid abrupt steeringmovements.
The tire pressure monitor has a yellow warninglamp in the instrument cluster for indicatingpressure loss or a malfunction. Whether thewarning lamp flashes or lights up indicateswhether a tire pressure is too low or the tirepressure monitor is malfunctioning:
Rif the warning lamp is lit continuously, the tirepressure on one or more tires is significantlytoo low. The tire pressure monitor is not mal-functioning.
Rif the warning lamp flashes for around aminute and then remains lit constantly, thetire pressure monitor is malfunctioning.
In addition to the warning lamp, a messageappears in the multifunction display. Observethe information on display messages(Ypage 213).
It may take up to ten minutes for a malfunctionof the tire pressure monitor to be indicated. Amalfunction will be indicated by the tire pres-sure warning lamp flashing for approximatelyone minute and then remaining lit. When themalfunction has been rectified, the tire pressurewarning lamp goes out after a few minutes ofdriving.
The tire pressure values indicated by the on-board computer may differ from those meas-ured at a gas station with a pressure gauge. Thetire pressures shown by the on-board computerrefer to those measured at sea level. At highaltitudes, the tire pressure values indicated by apressure gauge are higher than those shown bythe on-board computer. In this case, do notreduce the tire pressures.
The operation of the tire pressure monitor canbe affected by interference from radio transmit-ting equipment (e.g. radio headphones, two-wayradios) that may be being operated in or near thevehicle.
Checking the tire pressure electroni-
cally
XMake sure that the SmartKey is in positionHin the ignition lock (Ypage 123).
XPressYoreon the steering wheel toselect theServ.Serv.menu.
XPress thecordbutton to selectTire PressureTire Pressure.
XPress thevbutton.The current tire pressure of each tire is shownin the multifunction display.
If the vehicle was parked for longer than20 minutes, theTire pressure will beTire pressure will bedisplayed after driving a few minutesdisplayed after driving a few minutesmessage is shown.
After a teach-in process, the tire pressure mon-itor automatically detects new wheels or newsensors. As long as a clear allocation of the tirepressure value to the individual wheels is notpossible, theTireTirePressurePressureMonitorMonitorActiveActivemessage is shown instead of the tire pressuredisplay. The tire pressures are already beingmonitored.
If an emergency spare wheel is mounted, thesystem may continue to show the tire pressureof the wheel that has been removed for a fewminutes. If this occurs, note that the value dis-played for the position where the spare wheel isfitted is not the same as the current tire pres-sure of the emergency spare wheel.
Tire pressure monitor warning mes-
sages
If the tire pressure monitor detects a pressureloss in one or more tires, a warning message isshown in the multifunction display. The yellowtire pressure warning lamp then lights up.
RIf thePlease Correct Tire PressurePlease Correct Tire Pressuremessage appears in the multifunction display,the tire pressure in at least one tire is too low.The tire pressure must be corrected when theopportunity arises.
RIf theCheck Tire PressureCheck Tire Pressuremessageappears in the multifunction display, the tirepressure in one or more tires has droppedsignificantly. The tires must be checked.
RIf theTireTirePressurePressureWarningWarningTireTireFail‐Fail‐ureuremessage appears, the tire pressure in oneor more tires has dropped suddenly. The tiresmust be checked.
Observe the instructions and safety notes in thedisplay messages in the "Tires" section(Ypage 213).
If the wheel positions on the vehicle are rotated,the tire pressures may be displayed for thewrong positions for a short time. This is rectifiedafter a few minutes of driving, and the tire pres-sures are displayed for the correct positions.
Tire pressure299
Wheels and tires
Z

PSI (pounds per square inch)
A standard unit of measure for tire pressure.
Aspect ratio
Relationship between tire height and tire widthin percent.
Tire pressure
This is pressure inside the tire applying an out-ward force to each square inch of the tire's sur-face. The tire pressure is specified in pounds persquare inch (psi), in kilopascal (kPa) or in bar.The tire pressure should only be corrected whenthe tires are cold.
Cold tire pressure
The tires are cold:
Rif the vehicle has been parked with the tiresout of direct sunlight for at least three hoursand
Rif the vehicle has not been driven further than1 mile (1.6 km)
Tread
The part of the tire that comes into contact withthe road.
Bead
The tire bead ensures that the tire sits securelyon the wheel. There are several steel wires in thebead to prevent the tire from coming loose fromthe wheel rim.
Sidewall
The part of the tire between the tread and thebead.
Weight of optional extras
The combined weight of those optional extrasthat weigh more than the replaced standardparts and more than 2.3 kg (5 lbs). Theseoptional extras, such as high-performancebrakes, level control, a roof rack or a high-per-formance battery, are not included in the curbweight and the weight of the accessories.
TIN (Tire Identification Number)
This is a unique identifier which can be used bya tire manufacturer to identify tires, for examplefor a product recall, and thus identify the pur-chasers. The TIN is made up of the manufactur-er's identity code, tire size, tire type code andthe manufacturing date.
Load bearing index
The load bearing index (also load index) is a codethat contains the maximum load bearing capa-city of a tire.
Traction
Traction is the result of friction between the tiresand the road surface.
Treadwear indicators
Narrow bars (tread wear bars) that are distrib-uted over the tire tread. If the tire tread is levelwith the bars, the wear limit of